Unit B1d - Problems in the Drylands Environment


Unit B1d


People who live in desert or drylands areas are usually much more aware of the limitations of their environment because they are so dependent on scarce water resources and variable vegetation. That is why there is a special unit on drylands problems. There are parallel units on other special environments, like islands and mountains.

The deserts and drylands cover major parts of most continents, particularly Asia, Africa, North America and Australia. With climate change, rainfall is expected to decrease in many warmer parts of the planet, so more places will become drylands and droughts will become more frequent. Many more people will live in water-stressed areas.


The following are qualitative descriptions of the most pressing environmental concerns facing most dryland countries.

Water Shortage

While heavy rains may occur in drylands, they can be irregular from season to season and from year to year. Most of the time water is scarce, and limits the kinds of development that are possible. Human settlements may cluster around rare sources of water like rivers, springs, wells and oases. Traditional cultures in such areas developed ways of finding, conserving and transporting water. There were often special techniques of land management or works constructed to capture and retain rainwater, or to encourage groundwater recharge. In some coastal areas, trees or structures were used to condense moisture from the damp sea air.

In some drylands, agricultural areas are irrigated with water from dams or rivers, or pumped from underground aquifers. This is not always sustainable. As the water evaporates, it leaves salt behind, which may accumulate until the soil is so saline that nothing will grow there. It takes more water to flush the salt from the soil and carry it away. Also many irrigated drylands depend on "fossil" groundwater left from earlier climate periods, or extract water from wells faster than it is recharged by rainfall. If the water level in the wells is dropping, and water must be pumped from deeper in the ground, this is a sign of over-use. Pumping water from deep underground also requires lots of energy. Eventually there will be no more water, and such agriculture will collapse.

Soil Loss

The soil resource, the basis for agriculture, is often fragile where drought and loss of vegetation, and damage to desert crusts by motorized vehicles, leave the soil vulnerable to wind erosion, and water erosion during rare heavy rainfall and flash floods. Many drylands supported drought-tolerant plants that protected the soil from wind and rain, but overgrazing or land clearing for agriculture can remove this protection. High winds can remove so much soil that dust storms result, carrying away tonnes of soil. In the Sahara, dust storms are now so bad that the dust is carried to the Black Sea, to Europe or even across the Atlantic Ocean to the Caribbean. The dust blown from the plateaus of northern China now crosses the Pacific Ocean to North America.

Endangered Species

The problem of the conservation of nature is particularly critical in drylands where limited animal and plant populations are easily over-exploited. Habitats are fragile and easily damaged. There may be competition with humans for water resources, and with domesticated animals for food supplies. Drylands provide little cover for animals to hide from hunters. Desert species can easily become rare, or even be lost all together.

While a number of countries have made great efforts in setting aside protected areas, the needs far exceed the means, and providing adequate enforcement is very difficult. The best hope is for local people to themselves understand the need to protect nature in their area.

Plant and tree cover

Another major environmental concern for the future of drylands is the steady reduction in trees, grass and other vegetation. This not only represents the loss of a significant productive resource, but contributes to many subsidiary problems such as water shortages, soil erosion, and loss of habitat for endangered species. While many countries have tree replanting programmes, these have rarely been more than marginally successful. Yet restoring vegetation can be the key to rehabilitating marginal lands. This may also require controlling overgrazing. Since plants help to improve the soil and trap moisture, the result can be to recreate productive and useful land.

Land Use and Land Tenure

In drylands with limited natural resources, efficient use must be made of the scarce resources of the land to meet the needs of the people for water, food, building materials and reasonable quality of life, and to maintain the functioning of natural systems on which all these depend. The nomadic lifestyle of many desert and dryland peoples made it possible to live off of limited resources over wide areas, and to seek out whatever was available in a highly variable environment, without over-using the land. Unfortunately growing populations, encroachment of more sedentary communities, and new technologies are modifying and limiting nomadic land uses and migrations. The systems are breaking down and the land suffers as a result.

Traditional systems of land and resource tenure were often effective before European contact in maintaining the fair allocation and wise management of scarce resources in drylands. Faced with increasing conflicts over land, they are now breaking down. European systems of individual freehold ownership are no improvement in this respect. The resulting vacuum allows anarchic development, resource abuse and destruction without the possibility of imposing modern systems of zoning or control in the common interest. Conflict between farmers and herders is frequent. While some land is abused, other areas are neglected. Restoring or building on customary systems of management may be the most acceptable and effective approach in drylands where this is still possible.


Another group of environmental concerns are not as widespread as those above, affecting only a few dryland countries, but they are significant in the local areas affected.


Mining is the most significant economic activity in some dryland areas, and it is inevitably accompanied by serious environmental problems. These include the disposal of mine wastes, tailings and processing wastes, erosion problems and the pollution of rivers in mined areas, loss of natural habitat or of land with agricultural potential, and the abandonment of unusable wastelands once the mining has ended. While new mines today are generally subject to strict environmental controls, older mines and areas abandoned after earlier mining continue to present serious environmental problems.

Human Habitat

There are also problems of the human habitat in most dryland countries, particularly involving housing and sanitation. With water so scarce, water sources in villages and towns are particularly susceptible to pollution by animals and human wastes. As people are forced off degraded drylands or unable to support themselves through a drought, they migrate to urban areas, resulting in overcrowding and makeshift construction with consequent health problems. Some cities now have at least partial sewage treatment, but the problems of urban pollution in general are far from solved.

Domestic Waste

One problem in dryland areas linked to water shortages is the safe disposal of domestic wastes, particularly human wastes and urban sewage. The technologies of water-borne sewage disposal are inappropriate where water is very limited. Few countries have adequate waste collection and treatment facilities even in the most developed urban areas, and those that exist are costly and seldom properly maintained. In spite of considerable efforts at rural sanitation, facilities in many rural areas are still rudimentary or entirely lacking. The result is serious health problems.

It is only in the last two decades that countries have begun to pay serious attention to this problem, but the investments required to collect and treat domestic wastes are such that progress is very slow.


The problem of radioactivity is a special case in several dryland areas in central Asia, western North America, the Sahara and Australia, as deserts were seen as safe locations for testing nuclear weapons. Significant areas have been contaminated with radioactive materials, making them unsafe for most human uses. Uranium mines also occur in some dryland areas, and can contaminate land and water courses.


The above problems all contribute in one way or another to the most critical environmental issue facing dryland areas: the sustainable use and management of their limited resources. Population growth per se is not always the most important factor; some drylands have rapidly increasing populations, while on others the population is actually declining through emigration. Nevertheless, human activities are leading everywhere to a gradual (or not so gradual) erosion in the resource base on which the local residents depend for survival. Since the limits to resources are much closer in drylands, there is less room for error.

It is clear that the solution of these problems of the environment and of sustainable resource use will require management skills and a good scientific understanding of the dryland environment. Unfortunately, skilled people and scientific infrastructure are sorely lacking in dryland regions. The few scientific institutions are staffed largely by expatriates. In the past there were traditional experts on resource management at the local level, but more than a hundred years of missionary activity, colonization, European education and modernization have largely destroyed this knowledge and the traditional management systems through which it was applied.

If the peoples of drylands are to ensure for themselves a satisfactory environmental future, they must take measures to reverse the steady erosion in their resource base and to stabilize their populations within the carrying capacity of their land and resources, even if this means modifying what they see as deeply held cultural values. They must increase efforts to restore damaged resources, and to achieve comprehensive management of different resource uses and development activities, particularly in the critical areas where water is available. This will be very difficult, as it requires questioning some of the development assumptions and goals inherited from former colonial masters or copied from elsewhere. It is clear from the above list of environmental concerns that drylands require unique forms of development adapted to the limitations of the environment, and drawing as much from the traditional societies that successfully lived within those limits for generations as from the modern world.

A comparison of the environmental concerns of dryland areas with those of industrialized societies shows a profound difference of emphasis, at least in the short term. The pollution resulting from modern technological development is much less important than the need for sustainable management of the natural resource base. Drylands living with limited resources are a precursor of other regions, facing now what must become the long-term preoccupation of the whole world as resource degradation approaches the limits of the planet.



Which of these environmental problems are the most important in your country?

Why are they so important?

Which problems are not significant where you are?

Why not?

Which problems are caused primarily by local people?

Have some problems been imported from outside?

Can the government solve all these problems?

What can you do to solve environmental problems where you are?

Instructions for trainers in the use of this unit

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Last updated 30 July 2008